Single fiber-working, SFW, networks allow to reduce the number of required fibers in a system. Various DWDM and CWDM SFW architectures are available. All conventional SFW architectures have in common that the transmit wavelength is different from the receive wavelength. It is necessary to transmit and receive a signal at a different wavelength because otherwise fiber reflections of the optical fiber can result in severe transmission penalties. This has in particular a negative impact on 100G+ transponders using coherent detection. Because of space and power restrictions, 100G+ transponders use the same laser on the transmission side and reception side. In dual fiber-working systems, this does not pose a restriction on its operation as the transmit and receive wavelength are typically the same. However, in a single fiber-working, SFW, system, the transmit and receive wavelength must be different and as such these 100G+ transponders cannot be used in a single fiber-working architecture. Accordingly, there is a need to provide a method and an apparatus for enabling a single fiber-working where data is transportable through a single optical fiber SOF which allows the use of dual fiber-working, DFW, transponders.